A power supply device includes a power source unit, and a transformer disposed therein may have a size corresponding to nearly one-third of the volume of the entire power source unit.
A transformer includes a core, a bobbin, a winding, and the like. Even when a transformer includes a small amount of components, securing a space for a creepage distance required between windings and a core, winding insulating tapes on windings of a primary coil and a secondary coil to satisfy safety requirements, and the like, complicate a manufacturing process thereof.
Also, in the case of winding coils, coil turns or winding positions may not be equal or uniform, according to operators.
Thus, in order to miniaturize transformers and simplify manufacturing processes thereof, a method for developing a transformer provided with a new structure is required.
Patent document 1 discloses a transformer using a coil in a thin film substrate and a winding coil inserted into a magnetic pole portion of a core. [Related Art Document]    (Patent Document 1) Japanese Patent Publication No. 3437428